Magnesium Anthracene System-Based Electrolyte as a Promoter of High Electrochemical Performance Rechargeable Magnesium Batteries

Abstract

The development of efficient, inexpensive, and safe rechargeable batteries for large-scale environmentally benign cells is one of the key requirements to accommodate and satisfy various technological applications. To date, the development of magnesium battery as a promising candidate for next-generation battery systems has been hindered by the lack of high performance and stable electrolyte. In this work, we have developed an original, safe, and high-performance class of electrolytes based on a simple mixture of commercially available compounds, that is, Mg(TFSI), anthracene, MgCl, and diglyme solvent. We have proven that anthracene induces stabilization of the reduced form of magnesium involving reversible magnesium plating/stripping with very high current density. The electrolyte investigated exhibits an unprecedented electrochemical stability window of up to 3.1 V, whereas MgCl addition allows the improvement of the Mg/electrolyte interface properties and enables a large cyclability of Mg/MoS Chevrel phase cell, allowing one to reach high performances.

Halide‐Based Materials and Chemistry for Rechargeable Batteries

“…When the Mg(TFSI) 2 /MgCl 2 /DME electrolyte was applied in a Mg‐S battery, it produced a better cycling stability than all previously reported Mg‐S batteries (Figure ) . Another strategy to improve the electrochemical performance of the Mg(TFSI) 2 ‐based electrolyte was the use of an anthracene additive, which yielded an electrochemical stability window of up to 3.1 V versus Mg . The further addition of a slight amount of MgCl 2 could enhance the uniform reactivity.…”

“…[202] When the Mg(TFSI) 2 /MgCl 2 /DME electrolyte was applied in aM g-S battery,i tp roduced ab etter cycling stability than all previously reported Mg-S batteries ( Figure 12). [203] Another strategy to improve the electrochemical performance of the Mg(TFSI) 2 -based electrolyte was the use of an anthracene additive,w hich yielded an electrochemical stability window of up to 3.1 Vversus Mg. [204] Thef urther addition of as light amount of MgCl 2 could enhance the uniform reactivity.Concepts similar to that of the Mg(TFSI) 2 and MgCl 2 combination have been reported, for example,c ombinations such as Mg(HMDS) 2 -4 MgCl 2 , [205] (DTBP)MgCl-MgCl 2 (DTBP = 2,6-di-tert-butylphenolate), [206] ROMgCl-MgCl 2 , [207] and magnesium ethoxide (Mg-(OEt) 2 )-MgBr 2 . [208] Overall, the chloride ion has ap ositive effect on the properties of Mg electrolytes by forming the new electrochemical active species Mg 2 Cl 3 + /MgCl + and acting as ar efreshing reagent to break down the passivation films on Mg surfaces.H owever,t he Cl À ion can also attack other metallic or electrophilic materials during the electrochemical processes,t hus limiting its applicability.G ood compatibility between the electrolyte and the current collector is essential in battery systems.T he corrosion problem of chlorinecontaining electrolytes should be considered in regard to its practical utility.…”

A Stable Solid Electrolyte Interphase for Magnesium Metal Anode Evolved from a Bulky Anion Lithium Salt

“…To further verify the protective effects of this SEI on Mg surface, the cycled Mg electrodes were taken out from the Mg/Mg cells (with LBhfip/DME) to investigate its compatibility with Mg(TFSI) 2 /DME electrolyte. It is known that Mg(TFSI) 2 can chemically react with Mg metal to form passivation layer on the Mg anode surface, which severely hinders its reversible Mg plating/stripping . As shown in Figure g, the fresh Mg electrodes experience extremely high and rapidly increased overpotential during galvanostatic cycling in the Mg/Mg symmetric cell with Mg(TFSI) 2 /DME electrolyte, which is apparently caused by the Mg‐surface passivation as a result of reductive decomposition of TFSI − anion.…”

Halogenid‐basierte Materialien und Chemie für wiederaufladbare Batterien

“…Als der Mg(TFSI) 2 /MgCl 2 /DME‐Elektrolyt in die Mg‐S‐Batterie eingesetzt wurde, produzierte dieser die beste Zyklenstabilität von allen zuvor berichteten Mg‐S‐Batterien (Abbildung ) . Eine andere Strategie, die elektrochemische Leistung des Mg(TFSI) 2 ‐basierten Elektrolyten zu verbessern, war die Nutzung eines Anthracen‐Additivs, was ein elektrochemisches Stabilitätsfenster von bis zu 3.1 V vs. Mg erzielte . Die weitere Zugabe einer geringen Menge MgCl 2 konnte die uniforme Reaktivität erhöhen.…”

“…Mg erzielte. [204] Die weitere Zugabe einer geringen Menge MgCl 2 konnte die uniforme Reaktivitäte rhçhen. Zu der Mg(TFSI) 2 -und MgCl 2 -Kombination ähnliche Konzepte wurden berichtet, beispielsweise Kombinationen wie Mg(HMDS) 2 -4MgCl 2 , [205] (DTBP)MgCl-MgCl 2 (DTBP = 2,6-Di-tert-butylphenolat), [206] ROMgCl-MgCl 2 [207] und Magnesium-Diethanolat Mg(OEt) 2 -MgBr 2 .…”